If you have noticed that much of the waters in Burrard Inlet are looking red, you are not alone.

There were some initial concerns by locals about an oil or diesel spill, but the cause of the phenomenon has to do with a massive red algae bloom, according to the Vancouver Sun.

It is also known as red tide, which forms quickly when the right conditions are present. These phytoplankton, a plant-like organism, often form in warm temperatures and can blossom when fertilizer is heavily present.

They are most common in fresh water and are a frequent occurrence in the Great Lakes, including on Toronto’s Lake Ontario waterfront.

The growth of green algae is currently an annual issue at Burnaby Lake and Deer Lake due to the downhill drain of fertilizers into the waters.

Types of red tide can be particularly harmful to birds, fish and other marine mammals. Humans that swim in waters with red algae or consume seafood contaminated with red tide toxins can become seriously ill.

The algae in Vancouver’s local waters should disappear within a few short days.